Smoke-consuming and fuel-economizing apparatus for furnaces and the like.



J. THOMAS.

.SMOKE GONSUMING AN D FUEL EGONOMIZING APPARATUS FOR FURNACES AND THELIKE.

APPLIOATION FILED JUNE 10, 1911.

Patented June 18, 1912.

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J. THOMAS. SMOKE GONSUMING AND FUEL EGONOMIZING APPARATUS FOR FURNACESAND THE LIKE.

APPLICATION FILED JUNE 10, 1911.

Patented June 18,1912.

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JOHN THOMAS, OF KENILWORTH, ENGLAND.

Specification of Letters Patent.

Patented June 18, 1912.

Application filed June 10, 1911. Serial No. 632,330.

To all whom it may concern:

Be it known that I, JOHN THOMAS, a subject of the King of Great Britainand Ireland, and a resident of Kenilworth, VVarwickshire, England, haveinvented certain new and useful Improvements in Smoke- Consuming andFuel-Economizing Apparatus for Furnaces and the Like; and I do herebydeclare the following to be a full, clear, and exact description of thesame.

This invention relates to improvements in smoke consuming and preventingand fuel economizing apparatus forfurnaces and the like, wherein a gridon the fire door, automatically opened at the time of stoking, isautomatically and gradually closed by a device against the resistance ofliquid forced by a piston through a regulable passage, so that air isallowed to enter above the fire bars to burn the smoke formedimmediately after sto-king, and such air supply is cut off when the coalno longer tends to choke the ordinary air supply through the grate.

In the accompanying drawings :-Figure l is a front elevation of anapparatus constructed according to the present invention; Fig. 2 is aplan thereof; Fig. 3 is a sectional plan on 8-3, Fig. 1; Fig. 4 is asectional elevation on 4c-4, Fig. -1; Fig. 5 is a sectional elevation on55, Fig. 1, on an enlarged scale; Fig. 6 is a part sectional elevationon 66, Fig. 5; Fig. 7 is a sectional plan on 77, Fig. 5; Fig. 8 is atransverse section of a furnace through the back bridge plate, lookingbackward; and Fig. 9 is a longitudinal sect-ion on 9-9, Fig. 8. Fig. 10is a part longitudinal sectional elevation;

According to the present invention a grid, at, is adapted to slidevertically on a gridlike fire door, I), and a cup leather piston, 0,working within and engaging the walls of a preferably verticallyarranged cylinder, cl, is adapted to control the closing of the grid,at. The grid, at, is mounted between vertical guide, 6 on the fire door.

6 represents stops on the fire door engaging slots, a in the-grid, a,for support ing the latter in its lowest position.

The fire door, byis hinged to the furnace front, 6, as at 6 The cylinderis mounted on the furnace front by bolts or the like, f. The piston, 0,is normally urged to one end, in the case illustrated, the top, of itsstroke, by a spring, preferably a coiled spring, 9,

mounted within the cylinder, or surroundlng the piston rod, 0

The fire door 1s provided with a cam, 5

or equivalent means, made fast to the door so as to turn therewith andadapted as the door is opened to act on one end, M, of a lever, it, orlever system, the other end, W, of which engages or rests upon thepiston rod. The ends of the lever are preferably provided withanti-friction rollers, z, i, as shown.

The construction and arrangement is such that as the fire door is openedthe piston is forced against the spring to one end, in the caseillustrated the bottom, of its stroke, and that when the fire door isclosed and the lever, h, is free to resume its original position, thespring tends to return the piston to the top of its stroke.

The grid, a, is connected to the piston rod by a flexible cable, j, orthe like, attached to the grid, preferably in an adjustable manner, asat j and guided over or around pulleys, is, k 72 or the like,respectively arranged vertically above or in line with the grid, thefire door hinge, and the axis of the piston rod or approximately so. Thepulley, is, is mounted on the fire door and the pulleys, 70 76 on thefurnace front or other connection, 7', and that when the fire door isclosed and the piston'is raised by the spring, the grid is allowed toclose by its own weight, the spring merely serving to force the pistonupward. The piston is mounted on the piston rod, so that liquid withwhich the cylinder is charged is free to pass around the piston from thelower end of the cylinder to the upper end when the piston is moveddownward by the lever, it, against the spring thereby dispensing withthe use of clack valves on the piston, but, the piston resists movementof itself by the spring.

The piston rod, 0 which may form the piston block or pass therethrough,is made hollow, as at 0 and provided with a needle or similar valve, n.The stem, m of the valve is adapted to be adjusted in position byaneccentric, 0, on the piston rod, acting between stops or within astrap, m on the valve stem. The piston rod passes through a stuflingbox, 6Z and the top end of the cylinder has an inwardly extending bossor flange, (Z adapted to serve as a stop for the piston and preventdamage thereto.

(Z is a filling aperture which is normally closed by a plug.

The valve stem at its upper end passes through a stufling box, 0 and theeccentric is supported in bearings, 0 a, in an extension, 0, screwedonto the piston rod.

0 is a plug held in the extension, 0 and carrying a loop, 0", to whichthe cable, 7', is attached.

The construction and arrangement is such that by adjusting the positionof the eccentric by a hand wheel, 0 marked with a scale in conjunctionwith an index on the piston rod, or by a lever or pointer working over ascale on the piston rod, the amount of opening of the valve may bereadily and accurately controlled. The valve is adapted to close againsta seat, a provided at the lower end of the passage, 0 which opens intothe lower and upper ends of the cylinder, as shown.

The valve serves to allow the liquid to pass in a greater or less timefrom the upper end of the cylinder to the lower end through the passage,0 when the fire door is closed and the spring tends to raise the piston,and thereby regulates the closing of the grid by its own weight asaforesaid.

A draft door, 9, is provided at the back end of the fire pit to admit asecondary air supply at the back of the fire bridge, 9. The door, 39, ispivotally mounted, as at 29 in brackets, r, on a transverse plate, 0",which supports the back bridge plate, q, and when shut is adapted toliein an inclined position against side plates or shrouds, 1' m'dc Fig. 9.The door, 72, is actuated by a counterweighted cam, s, eccentric, or thelike, mounted on a rotary spindle, 5 supported in bearings, 8 on one ofthe side plates, 7. The cam is operated by an arm or, a lever, 8connected, ats, to a flexible cable, 2?, or a rod and cable or the like.The cable, t, passes around suitably arranged pulleys, t t and isconnected with the piston rod.

The construction and arrangement is such that as the fire door isopened, the draft door is opened, and as the grid is closed the draftdoor is closed, the draft door commencing to close at the same time asthe grid commences to close. The cam or the like is made of such a throwthat it opens the draft door quicker during the latter part of thestroke than during the earlier part, and allows the door to closequicker during the earlier part of the stroke than during the latterpart to obtain a better combustion of the smoke. The inclined positionof the draft door when shut insures its proper closure.

The apparatus is of advantage, inter alia, in that the cup leatherpiston is more certain in its action and offers less resistance to theopening of the fire door than pistons fitted with clack valves ashitherto constructed.

A baffle plate or wall, w, is preferably built or arranged opposite andbehind the draft door to deflect the air toward the gases escaping overthe fire bridge, in known manner. A hood, a2, is preferably mounted atthe back of the fire door for deflecting the air entering through thegrid downward onto the dead plate or fore end of the grate, in knownmanner.

WVhat I claim as my invention and desire to secure by Letters Patentis 1. In smoke consuming and fuel economizing apparatus for furnaces andthe like, in combination, a grid-like fire door, a grid adapted to slidevertically on the fire door and tending to close by its own weight, acylinder adapted to be charged with liquid, a cup leather piston mountedwithin the cylinder and adapted to be moved freely in one direction, ahollow piston rod the interior of which is adapted to communicate withboth ends of the cylinder, an adjustable needle or similar valve in thepiston rod for cont-rolling the passage through the piston rod, a springtending to move the piston to one end of its stroke, a lever engagingthe piston rod, a cam on the fire door adapted to act on the lever sothat as the fire door is opened the piston is forced to one end of itsstroke against the action of the spring, and so that when the fire dooris closed the spring tends to return the piston to the other end of itsstroke, pulleys respectively arranged vertically above or in line withthe grid, the fire door hinge, and the axis of the piston rod orapproximately so. the first of such pulleys being mounted on the tiredoor and flexible means connecting the grid to the piston and guidedover said pulleys, so that as the fire door is opened the grid is openedby the piston pulling on the flexible connection, and when the fire dooris closed and the piston is movedby the spring, the grid is allowed toclose, substantially as described.

2. In smoke consuming and fuel economizing apparatus for furnaces andthe like, in combination, a grid-likefire door, a grid adapted to slidevertically on the fire door and tending to close by its own weight, acylinder adapted to be charged with liquid, a cup leather piston mountedwithin and engaging the walls of the cylinder and adapted to be movedfreely in one direction, a hollow piston rod the interior of which isadapted to communicate with both ends of the cylinder, an adjustableneedle or similar valve in the piston rod for controlling the passagethrough the piston rod, a spring tending to move the piston to one endof its stroke, a lever engaging the piston rod, a cam on the fire dooradapted to act on the lever so that as the fire door is opened thepiston is forced to one end of its stroke against the action of thespring, and so that when the fire door is closed the spring tends toreturn the piston to the other end of its stroke, pulleys respectivelyarranged vertically above or in line with the grid, the fire door hinge,and the axis of the piston rod, or approximately so, the first of suchpulleys being mounted on the fire door, and flexible means connectingthe grid to the piston and guided over said pulleys, so that as the firedoor is opened the grid is opened by the piston pulling on the flexibleconnec tion, and when-the fire door is closed and the piston is moved bythe spring, the grid is allowed to close, substantially as described. v

3. In smoke consuming and fuel economizing apparatus for furnaces andthe like, in combination, a grid-like fire door, a grid adapted to slidevertically on the fire door and tending to close by its own weight, acylinder adapted to be charged with liquid, a cup leather piston mountedwithin and engaging the walls of the cylinder and adapted to be movedfreely in one direction, a hollow piston rod the interior of which isadapted to communicate with both ends of the cylinder, an adjustableneedle or similar valve in the piston rod for controlling the passagethrough the piston rod, a spring tending to move the piston to one endof its stroke, means for moving the piston against the spring as thefire door is opened, means connecting the piston to the grid, a draftdoor at the back of the fire pit adapted to be operated OK the pistonrod to admit a secondary air supply at the back of the fire bridge andadapted to commence and finish closing at the same times as the griddoes and when shut to lie in an inclined position, a spindle, and a cam,on the spindle and adapted to be operated off the pistonrod, said camhaving its working face extending in a curve outwardly from adjacent tosaid spindle so as to have a variable throw whereby the draft door opensquicker during the latter part of its stroke than during the earlierpart and to allow the draft door to close quicker during the earlierpart of its stroke than during the latter part, substantially asdescribed.

4. In smoke consuming and fuel economizing apparatus for furnaces andthe like, in combination, a grid-like fire door, a grid adapted to slideon the fire door, a cylinder adapted to be charged with liquid, a pistonmounted within the cylinder and adapted to be moved freely in onedirection, a passage connecting the ends of the cylinder, means forcontrolling the passage, a spring tend ing to move the piston to one endof its stroke, a lever engaging the piston rod, a cam on the fire dooradapted to act on the lever so that as the fire door is opened thepiston is forced to one end of its stroke against the action of thespring, and so that when the fire door is closed the spring tends toreturn the piston to the other end of its stroke, pulleys respectivelyarranged vertically above or in line with the grid, the fire door hinge,and the axis of the piston rod, or approximately so, the first of suchpulleys being mounted on the fire door, and flexible means connectingthe grid to the piston and guided over said pulleys, so that as the firedoor is opened the grid is opened by the piston pulling on the flexibleconnection, and when the fire door is closed and the piston is moved bythe spring, the grid is allowed to close, substantially as described.

In testimony whereof I affix my signature in presence of two subscribingwitnesses.

JOHN THOMAS.

Witnesses:

ALFRED DAY, WALTER DAY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

